Employees have a new favorite perk, and it's not free craft-brewed beer, student loan repayment benefits or eco-friendly roof gardens at the office. It's much simpler: More time off.

In its 17th annual employee benefits trend survey released this week -- just as Spring Break season hit its peak -- MetLife found that more people are interested in having an unlimited vacation policy than any other "emerging" perk, such as onsite medical clinics, subsidized egg freezing benefits or even paid sabbaticals. The policies' implicit flexibility for taking time off, the survey found, was more appealing to employees of every age group than any other new benefit (with the exception of a phased retirement program to Baby Boomer-aged workers).